To provide fuel for the traveling motorist, there are numerous fuel retail outlets located throughout. There has recently been a trend toward the motorist pumping his own fuel at so-called self service fueling sites which offer convenience and lower prices. The self service fueling sites most often have a fuel dispensing system where the dispensers are controlled by a remote dispenser controller. The remote dispenser controller may be located in a building at the site such that the dispensing process is controlled by a site attendant, or it may be a card read system whereby the customer controls the dispensing process.
Generally, a fuel dispenser includes a pump, a fuel supply pipe, a flowmeter, a flow quantity signal generator, a fuel supply hose with nozzle, and a flow indicator. The pump has at one end a pipe connection to a fuel supply tank, and at the other end a hose connection to a fuel supply nozzle. The flowmeter measures the quantity of fuel being pumped, and the flow quantity generator generates a flow quantity signal from the flowmeter. The indicator indicates the quantity of fuel being pumped based on the flow quantity signal.
As previously stated, the dispensers are often controlled by a remote dispenser controller located in a building at the fueling site, or through a card system. The remote controller has a wire connection between the dispensers and controller for transferring data signals. The remote controller generally is a microcomputer based system with read-only-memory (ROM), read-and-write memory (RAM), and input/output ports for reading and storing information applied at the ports. Specific functions of the control systems are well known in the art, and widely used in the industry. The microprocessor based control systems may be in the form of a stand alone console, or in the form of a logic module which interfaces the dispensers to a cash register system, or a card read system. The principles involved are the same, and it is understood that the present invention relates to all such systems.
The dispenser controller sends data signals to the dispensers, and the dispensers send data signals to the controller. Data signals sent to the dispenser from the controller include price per gallon to be charged at corresponding pumps, preset limits to be pumped, and pump authorization. Data signals sent from the dispenser to the controller include pump identity (pump number), pump status, and dispensed fuel volume and value.
In brief, the present invention relates to a flow signal monitoring system for monitoring flow quantity data signals in the data wire without interrupting data signal flow. The flow signal monitoring system is connected to the data wire between the dispensers and controller, and it monitors the data signals without interrupting the communication between the dispensers and controller. All data signals in the data stream are monitored, however, the data signals relating to flow quantity are selected and processed, and all other data signals are discarded. This is accomplished by a data field selector which designates data fields to be selected, and further instructs the microprocessor to select and process designated signals, and to discard all other signals. Information on dispensed volume is stored in memory and can be latter down-loaded to other devices including tank monitoring systems, printing devices, and visual display devices. These are, however, to be taken only as illustrative examples in that data extracted and stored can be used in other ways.
One use for the present invention is in combination with tank monitors. Recent Federal law requires that underground fuel storage tanks be continuously monitored to identify any loses caused by leaks. Tank monitors are used to do this, and are widely used in the industry for this purpose. Tank monitors use a probe which is permanently mounted in the storage tank through a riser pipe. Most tank monitor probes operate on a capacitance principle to sense fuel height. The probe has a wire connection to a microprocessor based control center which processes and stores the information, which usually includes gallons of fuel, inches of water, inches of fuel, temperature of fuel, and ullage.
Tank monitoring systems monitor the amount of fuel in the tank by a probe; the present invention collects and stores information on the actual amount of fuel dispensed from a tank. Thus, the present invention provides a method for reconciling the actual amount of fuel dispensed with the information collected by the tank monitor. The present invention stores actual transactions for each fueling position in memory, and this information can be retrieved at any time for comparison with information taken from the tank monitor.
Another use of the present invention is with inventory control and inventory report preparation. Each fueling position in a dispenser has a mechanical counter for counting the amount of fuel dispensed, and it keeps a running total of these amounts. These values are recorded and displayed on a numbered wheel in the dispenser. It is practice in the industry for the attendant to record these values at the end of his shift. These valves can then be used for shift totals, daily totals, inventory control, and related. For the site attendant to record these values, he must go out to the dispenser and visually observe the numbers from the display and write them down. This can be an inconvenience. For example, if the attendant is alone he must temporarily interrupt all dispensing while he is outside away from the controller. In cold climates, going outside can be uncomfortable. The present invention provides a device from which the site attendant can obtain these values from inside. These values can be visually observed, or they can be printed out.